Tensioner mechanism for a portable movie screen

Claim 1

A PORTABLE PROJECTION SCREEN, COMPRISING: AN UPRIGHT STANDARD; AN ELONGATED HOLLOW SCREEN CASING; A FLEXIBLE SCREEN PROVIDED WITH A PAIR OF ROD MEMBERS ONE SECURED TO EACH OF THE OPPOSITE END PORTIONS OF SAID SCREEN, ONE ROD MEMBER BEING IN TH FORM OF A SPRING WOUND REEL JOURNALED IN THE CASING ABOUT WHICH THE SCREEN IS WOUND IN RETRACTED POSITION, AND THE OTHER ROD MEMBER BEING ADAPTED TO BE ATTACHED TO THE STANDARD TO EXPOSE THE SCREEN IN VIEWING POSITION; A SUPPORT MEMBER ATTACHED TO THE STANDARD AND HAVING A TRACK ON ITS FORWARD FACE; A SLIDE SECURED CENTRALLY OF THE CASING AND COOPERATING WITH SAID TRACK TO PERMIT LIMITED SLIDABLE MOVEMENT WITH THE CASING WHEN THE SCREEN IS IN VIEWING POSITION; A ROTATABLE CAM MEMBER; AND A PAIR OF PORTIONS ONE ON THE SLIDE AND THE OTHER ON THE STANDARD, ONE OF THE PORTIONS ROTATABLY MOUNTING THE CAM MEMBER WHEREBY ROTATION OF THE CAM MEMBER CAUSES THE CAM MEMBER TO ENGAGE THE OTHER OF THE PORTIONS TO FORCE THE SLIDE AND THE PORTION THEREON TO MOVE AWAY FROM THE OTHER ROD MEMBER WHEN THE SCREEN IS IN VIEWING POSITION TO STRETCH THE SCREEN TAUT BETWEEN THE ROD MEMBERS.